Sanitary napkin



A. A. BURGENI SANITARY NAPKIN Oct. 30, 1962 2 Sheets-Sheet 1 Filed Oct.'7, 1958 [IE l] DIME Oct. 30, 1962 A- A ,BURGENl y SANITARY NAPKIN FiledOCb. 7, 1958 2 Sheets-Sheet 2 A TORNEY 3,060,936 SANITARY NAPKIN AlfredA. Burgeni, Short Hills, NJ., assigner to Personal Products Corporation,a corporation of New .lersey Filed Get. 7, 1958, Ser. No. 765,786Claims. (Cl. 12S-290) This invention relates to absorbent products andmore particularly to absorbent products especially suitable for use asdisposable pads for catamenial purposes.

Absorbent pads of the type used for catamenial purposes are usuallyrelatively bulky and flat and rectangular. In use, they are subjected tosqueezing and distorting forces which, due to the size and shape of thepads, cause them to deform and to bend transversely to assume an linverted U shape. Such distortion is undesirable because after beingdistorted, the pad does not readily adapt itself to changes in bodycontours during movement. These forces and the resultant distortion alsoreduce the absorbing effectiveness of the pad. The problem is pronouncedwhere the absorbent pad has an absorbent core containing looselyintegrated fibrous material, as for example where the core containspredominantly short fibrous material, such as Wood pulp bers or cottonlinters. Cores 'of this type are not inherently resilient and springyand lack form stability and shape retention. They tend to mat readily,particularly when wetted, and do not spring back appreciably to maintainlContact with the body. It is necessary, therefore, to include othercomponents in a pad containing a core of this type to provide it withthese characteristics.

I have found that absorbent pads containing such cores can be madespringy and resilient and be made stable with good form and structuralstability by providing the core with a cover of fluid pervious materialwhich extends over the top and down the sides and at least partiallyacross the bottom of the core where it is secured and by furtherproviding a springy, resilient layer on the bottom of the core so thatthe pad will tend to spring back in use after being distorted. Theforces which tend to deform the absorbent pad are resisted by Ithe coverand the underlayer. Springiness, resilience and resistance todeformation may be imparted to the core by extending the edges of thecover across the bottom of the core in overlapping relationship, or byproviding a separate layer or layers of springy, resilient material onthe bottom surface of the core, and extensively bonding the materialunderlying the core to the core.

An important feature of my invention is the provision of a disposableabsorbent pad suitable for use as a sani- 'tary napkin which has aspringy, resilient layer of material, preferably liquid repellent, onthe underside thereof which is integrated with the core whereby the coreand the springy, resilient layer mutually contribute to 'impartspringiness and resiliency to the pad. My invention also contemplates aninexpensive absorbent pad obtained through the use of inexpensivematerials wherein the inexpensive materials may be used in certainportions of the pad without detracting from its absorbing effectiveness.Another feature of my invention is the provision of a pad containing acore of loosely integrated brous material which normally tends toseparate readily but which is confined within the cover, the ends of thepad being closed or nearly so by compacting and densitying the fibers inthe core at the ends.

Reference is made to the accompanying drawings and the followingspecification, wherein various embodiments of the invention areillustrated and described by way of example.

In the drawings:

FIG. 1 is a perspective View of an absorbent pad suitable for catamenialpurposes incorporating the invention;

3,9%,936 Patented ct. 30, 1962 FIG. 2 is a bottom View of the pad ofFIG. l illustrating the manner in which the cover, backing sheet andcore may be associated;

FIG. 3 is a sectional view of FIG. 2 along lines 3-3;

IG. 4 is a sectional View of another form of pad incorporating theinvention;

FIG. 5 is a view of the pad attached to a strip for holding the pad inposition on the body of the wearer;

FIG. 6 is a side View of FIG. 5; and

FIG. 7 is another form of holding strip with which the pad may beutilized.

Referring to the drawings, a pad l0 embodying the invention includes anelongated core of absorbent material l2, such as core of comminuatedwood pulp fibers, cotton linters, or other suitable material, coveredwith a liquid pervious material 14, such as a non-Woven fabric, on thetop, sides and partially on the bottom. The longitudinal side edges 16of the covering material extend under the bottom of the core a shortdistance inwardly towards its longitudinal axis to provide marginal edgeportions extending the length of the core on each side thereof.

The bottom of the core is covered with a backing sheet 18 which limpartsspringness, resiliency and resistance to deformation to the pad,especially transversely. lf desired, a material which is dierent fromthe covering material may be used. In this manner, materials which areless expensive than the covering material, and materials havingdifferent physical characteristics may be used. The material used as thebacking sheet is preferably a sheet of liquid repellent paper which isrelatively stiff, springy and resilient and deformation resistant incom- .parison to the core and the covering material so that thesecharacteristics will be imparted to the core and the cornpleted pad.

The respective components arranged as described above would shift withrespect to each other and would not be retained in their respectivepositions in use. To integrate the structure, the cover and backingsheet are attached to the absorbent core and in one form of theinvention, also to each other.

As illustrated in FIGS. 2 and 3, the cover and the backing sheet are sodimensione-d that the side edges of each overlap on the bottom of thecore -to provide marginal portions which extend the length of the pad.The side edges of the cover are arranged in overlapping relationshipwith the side edges of the backing sheet by positioning the side edgesof the cover under the side edges of the backing sheet and in contactwith the core of absorbent material.

The cover and the backing sheet are attached to the core by moisteningor applying an adhesive material to one surface of the core, placing thecover and the backing sheet over the core with the overlapping marginalportions of lthe cover and the backing sheet on the moistened side ofthe core and then subjecting the cover, backing sheet and the core inthe moistened portions to suflicient compression to bond the componentsor, Where moisture is used, to cause the formation of hydrate-bondsbetween fibers in the moistened and compressed areas. The compressionneed not extend completely and be continuous over the face of the pad,but is desirably limited to a patterned or intermittent compressionwhereby only portions of the pad are subjected to compression While theremaining parts are relatively uncompressed.

A suitable pattern, illustrated in FIGS. 2 and 3, is one which isintermittent in nature and may consist of a series of spaced, offset,rows of compressed areas 20 extending along the length of the pad. A row22 of compressed areas is positioned at the overlapping marginalportions of the cover and the backing sheet to join them together. Themarginal portions ofthe cover are placed next to the core so that itwill be bonded directly to the core. Satisfactory bonding may beobtained by employing a patterned compression roller which formscompressed areas on the bottom of the pad about 3 millimeters wide andabout 2 millimeters long and spaced about 4 millimeters apart. @ther:bonding patterns may be used and the bonding may be obtained by meansother than by the use of moisture and pressure, as by employing suitableadhesives, resins, thermoplastic materials, and the like.

By attaching the cover and the backing sheet to the absorbent core asdescribed above, the absorbent core, the cover, and the backing sheetmutually contribute to each other in imparting form and structuralstability to the pad and the physical characteristics of resiliency,springiness and the like. For example, when the pad so formed issubjected to the normal squeezing forces er1- countered in use, as inthe case of a sanitary napkin, it tends to assume an inverted U shapedue to its coniiguration. The top of the pad is subjected to tension andthe bottom of the pad to compression. By anchoring the side edges of thecover to the bottom of the core, the pad tends tol return to itsundistorted shape. Thus, the core and cover are retained in relativelyiixed position with respect to each other during transverse deformation.Springiness, resiliency and resistance to transverse deformation into aU shape are provided by the backing sheet, which is also attached to thebottom of the core and, in one form of the invention, to the side edgesof the cover whcih overlap the side edges of the backing sheet. Amaterial suitable for a hackingsheet has a high elasticity andresiliency and good springiness and resistance to compression, and maybe a two ply sheet of paper Weighing approximately 12 pounds per 2880sq. ft. and impregnated with a water repellent material such as aluminumrosinate.

The backing sheet is extensively secured or bonded to the absorbent corethroughout a large portion of their adjacent surfaces to prevent thebacking sheet from buckling and separating from the absorbent core whenthe pad yis subjected to deformation. If the backing sheet separatedfrom the core during deformation, it would not impart its springy andresilient characteristics to the pad with the result that the pad wouldnot tend to return to its original shape. If desired, one or more pliesof other material, such as one or more plies of absorbent tissue papermay be positioned on the back of the core to provide further resiliencyand elasticity. Diiferent types of materialmay also be used in variouscombinations, as for example by covering the bottom of theI core With alaminate of springy, resilient repellent paper positioned between pliesof absorbent paper tissue.

In the form of the invention illustrated in FIG. 4, the side edges ofthe cover and the backing sheet overlap on the lbottom of the, core.However, in thisform, the cover and the backing sheet are not attachedto each other at their marginal portions as in the embodiment describedabove in connection with FIGS. 1 through 3. Instead, themarginalportions 22 of the cover are attached tothe core a short distanceinwardlyV from its side edges while the backing sheet is attachedextensively to the core, as above. Y

A disposable absorbent padY incorporating the invention vmay be made inthe following manner. AA continuous web of comminutedV wood pulp abouttwo andY ve-eighths inches wide -andweighing about 1350 grainsper-squarefoot is formed by any well known operation. The surface of theweb which ultimately forms the bottom ofthe pad is sprayed witha fineVspray of water ito provide aY moisture pick upof approximately 60 grainsof water per one hundred square inches ofV web area. By spraying withaiine'spray of water'infthe amounts indicated, the moisture is limitedin application to the surface of the web andappreciable amounts of themoisture do not penetrate into the interior ofthe web. After sprayingwith moisture, a liquid pervious fabric, such as a non-woven fabricweighing approximately 220 grains per square yard is applied to coverthe top, sides and a portion of the bottom surface of the web to whichthe moisture has been applied. The side edges of the cover may extendover the side edges of the moistened surface of the web to form marginalportions about nine-sixteenths of an inch wide extending the length ofthe web, leaving an uncovered por-tion approximately one and one-halfinches wide extending centrally throughout the length of the web. Afterthe cover has been placed around the web the sheet of springy, resilientliquid repellent lpaper sufficiently wide to overlap the edges of thecover is placed over the uncovered portion of the web. The structure soformed is then embossed by passing through a device consisting of apatterned embossing roller and a smooth surfaced backing roller with thepatterned roller embossing the side of the web covered with repellentpaper. Suiiicient pressure is applied by the embossing roller tointegrate the respective parts of the pad and to obtain a coherent bondbetween the core and the repellent paper and the edges of the cover. Theformation of the coherent bond due to the presence of moisture and theapplication of pressure unites the respective elements.

If desired, the product so formed may be supplied in continuous lengths,e.g. as a roll of suicient length to provide ten to twelve individualpads which may be cut as needed. Preferably, individual pads are cutduring the manufacturing operation with rounded ends 24 as illustratedin the drawings. During the cutting operation, the ends of the pads andthe iibers in the core at the ends are densiiied and compacted to format least a partial closing of the ends, thus minimizing separation ofthe ii-brous material at the ends of the pad. The cutting operation,which may be performed with a reciprocating cutter and which may beconducted in the presence of the moisture sprayed on the surface of theweb, results in the application of compression to the ends of the piecebeing cut which causes a fusion or welding of the iibers in the ends ofthe pad.

The pad may be used as a disposable catamenial insert by inserting intoa panty, or it may be used as a complete napkin. In FIGS. 5 through 7,there are illustrated carrier strips which may be used to support thepad to form a complete napkin ready for use. In FIG. 5, there is shown astrip of fabric 26 such as a strip of 5gauze approximately 1 inch wideand 14 to 16 inches long which serves as carrier for the pad. The pad ispositioned on the top of the carrier strip so that the ends of thecarrier strip extend beyond the ends of the pad to provide attachingtabs. The pad is maintained in position on the carrier strip by adhesivetabs v28, such as tabs formed from pressure sensitive adhesive tape,having a portion thereof which is adhesively secured to the surface ofthe carrier strip and the remaining portion adhered to the top end'surface of the absorbent pad. This form of carrier strip is especiallysuitable for use with pads having repellent paper in the bottom becauserepellent paper does not stick readily to conventional'adhesive masses.Better adhesion in such cases is obtained'by adhering the ladhesive tabsto the cover on the top ofthe pad. In FIG. l7, instead of adhesive tabs,the carrier strip is provided with spacedradhesive surfaces 30 which areso positioned on the carrier strip as to adhesively contact theabsorbent pad placed upon the strip adjacent the ends ofthe pad therebysecuring the pad to the carrier strip. This form of carrier strip issuitable for useV with pads which have backing sheets which adherereadily to adhesive masses. It is to be understood that variations andchanges may made in the above described illustrative embodiments of theinvention. For example, one or more-layers of materials may be added orsubstitutedvin different combinations with the components of the pad andthat such" variations and changes are contemplated as withinl theinvention.

What is claimed is:

l. A sanitary napkin comprising a thick, elongated rectangular-shapedabsorbent member having spaced, parallel, longitudinally extending sideedges, said member including a core containing loosely integrated shortabsorbent ibers, a liquid pervious cover covering the top and sides ofsaid core and extending at least partially under the bottom thereof, thelongitudinal side edges of said cover being in alignment with thelongitudinally extending side edges of said core, said cover beingsecured at its side edges to said core, and a springy, resilient backinglayer covering the bottom of said core, said backing layer beingextensively and intermittently secured to said bottom of said core inspaced compressed areas, and maintained in intimate relationshiptherewith, said member having form stability in said rectangular shapeand being deformation resistant transversely.

2. A sanitary napkin comprising a thick, elongated, rectangular-shapedabsorbent member having spaced parallel,

longitudinally extending side edges, said member including a corecontaining loosely integrated short absorbent cellulosic fibers, aliquid pervious cover covering the top and sides of said core andextending at least partially under the bottom thereof, the longitudinalside edges of said cover being in alignment with the longitudinallyextending side edges of said core, said cover being secured at its sideedges to said core, and a springy, resilient backing layer covering thebottom of said core, said backing layer being extensively andintermittently secured by hydrate bonds to said bottom of said core inspaced compressed areas, and maintained in intimate relationshiptherewith, said member having form stability in said rectangular shapeand being deformation resistant trans- `versely.

3. A sanitary napkin comprising a thick, elongated rectangular-shapedabsorbent member having spaced, parallel, longitudinally extending sideedges, said member including a core containing loosely integrated shortabsorbent bers, a liquid pervious cover covering the top and sides ofsaid core and extending at least partially under the bottom thereof, thelongitudinal side edges 0f said cover being in alignment with thelongitudinally extending side edges of said core, and a springy,resilient backing layer covering the bottom of Said core, the side edgesof said cover and said backing layer overlapping, said cover beingsecured at its side edges to said core and to the side edge of saidbacking layer, said backing layer 6 being extensively and intermittentlysecured to said bottom of said core in spaced compressed areas, andmaintained in intimate relationship therewith, said member having formstability in said rectangular shape and being deformation resistanttransversely.

4. A sanitary napkin comprising a thick, elongated rectangular-shapedabsorbent member having spaced, parallel, longitudinally extending sideedges, said member including a core containing loosely integrated shortab- `sorbent cellulosic libers, a liquid pervious cover covering the topand sides of said core and extending at least partially under the bottomthereof, the longitudinal side edges of said cover being in alignmentwith the longitudinally extending side edges of said core, and aspringy, resilient backing layer covering the bottom of said core, theside edges of said cover and said 4backing layer overlapping, said coverbeing secured at its side edges to said `core and to the side edges ofsaid backing layer, said backing layer being extensively andintermittently secured by hydrate bonds to said bottom of said core inspaced, compressed areas, and maintained in intimate relationshipftherewith, said member having form stability in said rectangular shapeand being deforma-tion resistant transversely.

5. A sanitary napkin comprising an elongated carrier strip, anelongated, rectangular-shaped absorbent pad on said strip, the ends ofsaid strip extending beyond the ends of said pad forming attachmenttabs, and an adhesive tab at each end of the pad, each tab having aportion of its adhesive surface adhering to the surface of said stripbeyond the ends of said pad and another portion adhered to the endportion of the adjacent end of said pad at the top surface thereof tomaintain said pad in position on said strip.

References Cited in the tile of this patent UNITED STATES PATENTS860,111 Wright July 16, 1907 1,753,106 Barth Apr. 1, 1930 2,074,936Paterson Mar. 23, 1937 2,104,423 Hughes Ian. 4, 1938 2,408,508 CanavanOct. 1, 1946 2,649,858 Le Bolt Aug. 25, 1953 2,742,903 Lightner Apr. 24,1956 i 2,788,003 Morin Apr. 9, 1957 2,838,048 Kowalski June 10, 1958

